Τρίτη 7 Δεκεμβρίου 2021

Dual anticancer role of metformin: an old drug regulating AMPK dependent/independent pathways in metabolic, oncogenic/tumorsuppresing and immunity context

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Am J Cancer Res. 2021 Nov 15;11(11):5625-5643. eCollection 2021.

ABSTRACT

Metformin has been known to treat type 2 diabetes for decades and is widely prescribed antidiabetic drug. Recently, its anticancer potential has also been discovered. Moreover, metformin has low cost thus it has attained profound research interest. Comprehensing the complexity of the molecular regulatory networks in cancer provides a mode for advancement of research in cancer development and treatment. Metformin targets many pathways that play an important role in cancer cell survival outcome. Here, we described anticancer activity of metformin on the AMPK dependent/independent mechanisms regulating metabolism, oncogene/tumor suppressor signaling pathways together with the issue of clinical studies. We also provided brief overwiev about recently described metformin's role in cancer immunity. Insight in these complex molecular networks, will simplify application o f metformin in clinical trials and contribute to improvement of anti-cancer therapy.

PMID:34873484 | PMC:PMC8640802

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New insights into the functions of progesterone receptor (PR) isoforms and progesterone signaling

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Am J Cancer Res. 2021 Nov 15;11(11):5214-5232. eCollection 2021.

ABSTRACT

Progesterone, the ovarian steroid hormone, regulates a plentitude of biological processes in tissues ranging from the brain to bones. Recognizing the role of progesterone and its receptors in physiological processes and maladies can prevent and treat various diseases. Apart from its physiological functions, its role in developing diseases, especially breast cancer, is a recent topic of deliberation. There exists conflicting experimental and epidemiological evidence linking progesterone to breast cancer. This review tries to describe the physiological functions of progesterone and its receptors, genomic and non-genomic signaling, splice variants, and a different aspect of progesterone signaling. Furthermore, we seek to address or attempt to discuss the following pertinent questions on steroid hormone signaling; How does progesterone influence breast cancer progres sion? How does it change the molecular pathways in breast cancer with different receptor statuses, the specific role of each isoform, and how does the ER/and PR ratio affect progesterone signaling?

PMID:34873457 | PMC:PMC8640821

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DNA methylation markers in esophageal cancer: an emerging tool for cancer surveillance and treatment

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Am J Cancer Res. 2021 Nov 15;11(11):5644-5658. eCollection 2021.

ABSTRACT

Esophageal carcinoma (EC) is one of the most pervasive cancers in the world, with upwards of 500,000 new diagnoses, annually. Despite its prominence, advancements in the detection and treatment of EC have been marginal over the past 30 years and the survival rate continues to stay below 20%. This is due to the uncommonly heterogeneous presentation of EC which presents unprecedented challenges in improving patient survival and quality of care. However, distinct epigenetic alterations to the DNA methylome may provide an avenue to drastically improve the detection and treatment of EC. Specifically, the creation of novel biomarker panels that consist of EC-specific methylation markers have shown promise as a potential alternative to the more invasive, contemporary diagnostic methods. Additionally, growing insight into the biological and clinical properties of EC-spec ific methylation patterns have opened a window of opportunity for enhanced treatment; of growing interest is the application of "DNMT inhibitors" - a class of drugs which inhibit excessive methylation and have been shown to re-sensitize chemoresistant tumors. Here we provide a comprehensive review of the current advancements in EC DNA methylation to underscore a potential approach to its detection and treatment.

PMID:34873485 | PMC:PMC8640794

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m6A methyltransferase METTL3 promotes oral squamous cell carcinoma progression through enhancement of IGF2BP2-mediated SLC7A11 mRNA stability

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Am J Cancer Res. 2021 Nov 15;11(11):5282-5298. eCollection 2021.

ABSTRACT

As the key enzyme of the N6-methyladenosine (m6A) in eukaryotic messenger RNA, METTL3 plays an important role in tumor progression, but the exact mechanism by which METTL3 controls oral squamous cell carcinoma (OSCC) progression remains unclear. In this study, METTL3 expression in OSCC samples was analyzed by qPCR and immunohistochemistry. The effects of METTL3 suppression on OSCC cell lines were measured by CCK-8, Ki67 flow cytometry analysis, invasion transwell and wound healing assays. MeRIP-seq and RNA-seq analyses were performed to explore target gene of METTL3. RIP-qPCR and RNA stability assays were performed to explore the mechanism by which METTL3 regulated the target genes. Triptolide was used to evaluate its specific treatment effects on METTL3 in OSCC cells. BALB/c nude mice were used to establish orthotopic and subcutaneous xenograft models to verify the in vitro results. The results showed that METTL3 was upregulated in OSCC tissues compared with OSCC adjacent normal tissues, and its expression was associated with T stage, lymphatic metastasis and prognosis. METTL3 suppression impaired OSCC cells proliferation, invasion, and migration. MeRIP-seq and RNA-seq analysis identified that SLC7A11 mRNA was the m6A target of METTL3, which was verified by meRIP-qPCR, qPCR and western blot. METTL3 depletion decreased the stability of SLC7A11 mRNA, and IGF2BP2 as m6A reader was involved in this process. Moreover, METTL3 knockdown attenuated the binding between SLC7A11 mRNA and IGF2BP2, finally leading to accelerate SLC7A11 mRNA degradation. Triptolide inhibited METTL3-mediated SLC7A11 expression, thus suppressing malignancy of OSCC cells. In conclusion, the new finding of the manuscript is that METTL3 enhances the mRNA stability of SLC7A11 via m6A-mediated binding of IGF2BP2, which thus pr omotes OSCC progression, and triptolide inhibits OSCC by suppressing METTL3-SLC7A11 axis. Triptolide has a potential to be as an effective anti-OSCC drug targeted to METTL3.

PMID:34873461 | PMC:PMC8640804

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Targeting the oncogenic TBX3:nucleolin complex to treat multiple sarcoma subtypes

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Am J Cancer Res. 2021 Nov 15;11(11):5680-5700. eCollection 2021.

ABSTRACT

Sarcomas are diverse cancers of mesenchymal origin, with compromised clinical management caused by insufficient diagnostic biomarkers and limited treatment options. The transcription factor TBX3 is upregulated in a diverse range of sarcoma subtypes, where it plays a direct oncogenic role, and it may thus represent a novel therapeutic target. To identify versatile ways to target TBX3, we performed affinity purification coupled by mass spectrometry to identify putative TBX3 protein cofactors that regulate its oncogenic activity in sarcomas. Here we identify and validate the multifunctional phosphoprotein nucleolin as a TBX3 cofactor. We show that nucleolin is co-expressed with TBX3 in several sarcoma subtypes and their expression levels positively correlate in sarcoma patients which are associated with poor prognosis. Furthermore, we demonstrate that nucleolin and TBX3 interact in chondrosarcoma, liposarcoma and rhabdomyosarcoma cells where they act together to enhance proliferation and migration and regulate a common set of tumor suppressor genes. Importantly, the nucleolin targeting aptamer, AS1411, exhibits selective anti-cancer activity in these cells and mislocalizes TBX3 and nucleolin to the cytoplasm which correlates with the re-expression of the TBX3/nucleolin target tumor suppressors CDKN1A (p21CIP1) and CDKN2A (p14ARF). Our findings provide the first evidence that TBX3 requires nucleolin to promote features of sarcomagenesis and that disruption of the oncogenic TBX3-nucleolin interaction by AS1411 may be a novel approach for treating sarcomas.

PMID:34873487 | PMC:PMC8640805

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From development to cancer - an ever-increasing role of AGR2

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Am J Cancer Res. 2021 Nov 15;11(11):5249-5262. eCollection 2021.

ABSTRACT

Anterior gradient 2, AGR2, is a small, 20 kDa protein that plays a vital role in oxidative protein folding in the endoplasmic reticulum. AGR2 is involved in several signal transduction pathways that are essential for cell survival. It was initially discovered in the African clawed frog, Xenopus laevis, where it plays an important function in embryonic development. Akin to several other developmental genes, it is also frequently deregulated in cancer, where it plays a decisive role in tumor initiation, progression and metastasis. In this review, we have summarized currently known AGR2 functions, its expression and function in embryonic and cancer development, as well as its potential as a candidate tumor biomarker and promising new target for cancer immunotherapy.

PMID:34873459 | PMC:PMC8640830

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Synergistic radiosensitizing effect of BR101801, a specific DNA-dependent protein kinase inhibitor, in various human solid cancer cells and xenografts

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Am J Cancer Res. 2021 Nov 15;11(11):5440-5451. eCollection 2021.

ABSTRACT

DNA-dependent protein kinase (DNA-PK), an essential component of the non-homologous end-joining (NHEJ) repair pathway, plays an important role in DNA damage repair (DDR). Therefore, DNA-PK inhibition is a promising approach for overcoming radiotherapy or chemotherapy resistance in cancers. In this study, we demonstrated that BR101801, a potent DNA-PK inhibitor, acted as an effective radiosensitizer in various human solid cancer cells and an in vivo xenograft model. Overall, BR101801 strongly elevated ionizing radiation (IR)-induced genomic instability via induction of cell cycle G2/M arrest, autophagic cell death, and impairment of DDR pathway in human solid cancer cells. Interestingly, BR101801 inhibited not only phosphorylation of DNA-PK catalytic subunit in NHEJ factors but also BRCA2 protein level in homologous recombination (HR) factors. In addition, combination BR101801 and IR suppressed tumor growth compared with IR alone by reducing phosphorylation of DNA-PK in human solid cancer xenografts. Our findings suggested that BR101801 is a selective DNA-PK inhibitor with a synergistic radiosensitizing effect in human solid cancers, providing evidence for clinical applications.

PMID:34873471 | PMC:PMC8640799

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Morphometric analysis of the lumbar vertebrae and intervertebral discs in relation to abdominal aorta: CT-based study

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Surg Radiol Anat. 2021 Dec 7. doi: 10.1007/s00276-021-02865-9. Online ahead of print.

ABSTRACT

PURPOSE: Although lumbar discectomy is the most common procedure in spine surgery, reports about anatomical relations between discs and prevertebral vessels are limited. Aim of this research was to investigate morphometric of the lumbar region and the relations between intervertebral discs (IVDs) and abdominal aorta.

METHODS: 557 abdominal computed tomography scans were assess ed. For each spinal column level from Th12/L1 down to L4/L5, we investigated: intervertebral disc's and vertebra's height, width, length, and distance from aorta or common iliac artery (CIA). Those arteries were also measured in two dimensions and classified based on location.

RESULTS: 54.58% of patients were male. There was a significant difference in arterial-disc distances (ADDs) between genders at the levels: L1/L2 (1.32 ± 1.97 vs. 0.96 ± 1.78 mm; p = 0.0194), L2/L3 (1.97 ± 2.16 vs. 1.15 ± 2.01 mm; p < 0.0001), L3/L4 (2.54 ± 2.78 vs. 1.71 ± 2.61 mm; p = 0.0012), also for both CIAs (left CIA 3.64 ± 3.63 vs. 2.6 ± 3.06 mm; p = 0.0004 and right CIA: 7.96 ± 5.06 vs. 5.8 ± 4.57 mm; p < 0.001)-those ADDs were higher in men at all levels. The length and width of IVD increased alongside with disc level with the maximum at L4/L5.

CONCLUSION: Bifurcations of the aorta in most cases occurred at the L4 level. Collected data suggest that at the highest lumbar leve ls, there is a greater possibility to cause injury of the aorta due to its close anatomical relationship with discs. Females have limited, in comparison to males, ADD at L1/L2, L2/L3, and L3/L4 levels what should be taken into consideration during preoperative planning of surgical intervention.

PMID:34874459 | DOI:10.1007/s00276-021-02865-9

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Exoscopic visualisation with VITOM® 3D in paediatric cochlear implantation: preliminary results

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Abstract

3D exoscopy is an emerging visualisation technique designed to improve ergonomics and image quality during surgeries. We present a novel application of the VITOM® 3D exoscope in cochlear implantation (IDEAL Stage 2a prospective case series). The system enabled high-quality visualisation during both posterior tympanotomy and electrode insertion. Both the chief surgeon and the staff members rated the ergonomics of the system highly. 3D exoscopy is a useful alternative to conventional microscopy, but the two techniques remain to be directly compared in larger studies.

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Prediction of Oxygen Desaturation by Using Sound Data From a Noncontact Device: A Proof‐of‐Concept Study

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Objectives/Hypothesis

Prediction of the apnea-hypopnea index (AHI) from breathing sounds during sleep could be used to prescreen for obstructive sleep apnea (OSA). In addition, the oxygen desaturation index (ODI) is a known risk factor for developing cardiovascular disease in OSA patients. This study focused on estimation of ODI from a noncontact manner from sleep breathing sounds.

Study Design

Retrospective study.

Methods

Patients who visited the sleep center due to snoring or sleep apnea underwent polysomnography in lab overnight. Sound recordings were made during polysomnography using a microphone. After noise reduction, the sound data were segmented into 5 seconds windows and features were extracted. Binary classification and regression analyses were performed to estimate the ODI during sleep (model 1). This was re-tested after inclusion of body mass index (BMI) and age as additional features (model 2: BMI only, model 3: BMI and age).

Results

We included 116 patients. The mean age and AHI of all patients were 50.4 ± 16.7 years and 23.0 ± 24.0 events/hr. In binary classification, for ODI cutoff values of 5, 15, and 30 events/hr, the areas under the curve were 0.88, 0.93, 0.91, respectively, and accuracies were 85.34, 86.21, and 87.07, respectively. In regression analysis, the correlation coefficient and mean absolute error were 0.80 and 9.60 events/hr, respectively. In models 2 and 3, the correlation coefficient and mean absolute error were 0.82, 9.44 events/hr and 0.81, 9.6 events/hr, respectively.

Conclusion

Prediction of ODI from sleep sound seems to be feasible. Additional clinical feature such as BMI may increase overall predictability.

Level of Evidence

IV Laryngoscope, 2021

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Third molar surgical difficulty scales: systematic review and preoperative assessment form

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Med Oral Patol Oral Cir Bucal. 2021 Dec 7:24951. doi: 10.4317/medoral.24951. Online ahead of print.

ABSTRACT

BACKGROUND: The main objective of this systematic review was to collect the pre-existing scales for assessing the difficulty of third molar extraction. The secondary objective was to design a proposal for a preoperative evaluation protocol for the difficulty of third molar extraction.

MATERIAL AND METHODS: Two independent researchers conducted an electronic search in Pubmed (MEDLINE), Cochrane, and Scopus databases during March 2021. Included studies evaluated the prediction of the difficulty of surgical removal of impacted upper or lower third molars using new indices/scales or pre-existing scales with or without modifications. Articles referring to coronectomies or assessing pre-surgical difficulty using other tools were excluded. Neither language nor publication date restrictions were applied.

RESULTS: Out of 242 articles, 13 prospective cohort studies were finally selected. Seven developed new indices/scales, and 6 assessed the predictive ability of some pre-existing scales. Most of the indices/scales contained radiological variables and few added any patient-related variables. We proposed a preoperative assessment protocol of the difficulty of third molar extraction to facilitate treatment planning and/or considerate referral in cases of high difficulty. This proposal used patient-related, radiological and surgical variables.

CONCLUSIONS: Using a preoperative protocol to evaluate the surgical difficulty, including different patient-specific, radiological and surgical variables, could facilitate treatment planning, help clinicians prevent complications and assess the possibility of referral.

PMID:34874928 | DOI:10.4317/medoral.24951

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